Leveling rod



@f7/vend?? Jan. 13, 1931. A. LANGSNER LEVELING ROD Filed Aug. 29, 1927 7 www d 7 zza 'Patented Jan. 13, 19h31y i UNITED STATES 4Perla-1v'rsor-rllc`E ADOLPH LANGSNER, or CHICAGO, ILLINOIS, AssIGNoR To EUGENE .DIETZGEN CoM- PANY, or CHICAGO, ILLINOIS, A conroR-ATIoNoF DELAWARE LEVELING non Application inea August 29, 1927., serial No. 216,3n5.

My invention relates to lockingdevices for extensible leveling rods for holding the upper section in positive, locked relation, in fully extended position relative to the lower 5 section, so that-this adjustment of the two sections cannot be inadvertently disturbed.

Heretofore, in the construction vot thesev extensible leveling rods wherein the upper section carrying a target adjustable thereon is slidable relative to the lower section, which isadaptedV to the position vertically on the ground or other support, it has been customary to provide an adjustable clamping device for firmly holding the upper section in its extreme extended position on the lower section. Experience has shown, however, that inthe ordinary use o'f the leveling rod as thus extended, thatV after a measurement. had been taken and the operator had removed to a vdiilerent position to take a new measurement, he invariably, in the act of re-positioning the lower Vsection on the ground, permitted it to Vdrop slightly and impact against the'ground. The prior construction of clamping devices were not supiliciently effective to yprevent the shock of impact of this lower section against the ground to prevent the y'upper sectionv from moving downwardly slightly, thusldisturb- 3o ing the exact and accurate setting oftheupper sectionin its extreme extended position.

One ofthe objects of my presenty invention is to provide a locking device, and particularly an automatic locking device, fpr positively and iirmlyholding the upper section from inadvertent movement relative to the lowerv section when the upper section is in its-extreme extended position.

Another object of my present invention is to so construct this locking device that it will come into operation automatically asthe upper-section is slid along, and upwardly, `relative to the lower section, vso that when the upper section inally reaches its extreme extended position it will be positively locked. j Still anotherobject. of my invention resides in providing such a locking device vih of rra-positioning: the lower section on vthe pletely hidden from view when the sections non-extended or lowered posiber is adapted to give way to permit the other sectionto slide over it when shifted in one direction, but which member will jinstantly return to former position when the other member has passed beyond it, so that the yieldable member will` Vthen be in a position to prevent the return movement of the other member. .By arranging this yieldab-le member to operate whenthe sections of the leveling rod are not invertical position, the upper section will beheld by the` actionbi` gravity, `and the outward position of the yieldable member. VThis position will 'correspond to the extreme extended position oi. the upper section. j

r'These and other objects will be apparent from a perusal ofthe following specification when taken in connection with the accompanying drawings, wherein p Figure l is a sectional view of the upper and lower sections of my leveling rod when in lowered position.l

. Figure 2 is a corresponding vie'vv-thereofv when the upper tended. position.` j

Figure 3 is a perspective view of Figure f2.

section is in extreme ex- Figure 4, is a perspective View of vone formV of my spring interlock. i'

Figure' is perspective view of the upper and lower sections of the leveling rod when in lower position. v f

Figure 6 is a similar View with the vsections infully extended position.

` Referring now'to the drawings, my 'extensible 'leveling rod comprises a lower section 2 and an upper or movable section 4; the lower section-vin use is adapted to be `vertically positioned on the ground 'andthe j upper section'slides vertically on thellower section. y,These two sections are constructed sol that a target may slide along either one. In'taking certainmeasurementsit is necessary Ato extend the upper section Liso that the target on the upper section can be adjusted to greater' elevations.A In this instance the upper section is merely slid vertically upwardly to the lower section. ny desirable means may be utilized for holding the two sections in assembled relation, so that they may be free to slide upon each other relatively. In the present instance, I have shown the bottom portion of the upper section 4 provided with an ordinary type of Ueshaped clip 6, which encloses thelower section 2. In addition, prior devices have been provided with clamping means, including cooperative parts on the slidable sections for firmly holding the sections in out- \\\'ardly extended position. Heretofore such clamping means have taken several terms.l but in the present illustration I have preferred to use the particular clamping means which I have shown, and which generally comprise a rectangular hollow sleeve 8 secured to the face of the upper portion of the lower section 2. This sleeve is adapted to receive and to have slide therethrough, the upper section 1l, and this sleeve has been provided with an adjusting screw operated by a hand wheel 10 so to press against and hold the sections firmly.

My present invention consists in means positioned on the relatively movable sections at definite points thereon and con-V structed and arranged so that when the two sections slide relatively, so that the outer section is in extreme extended position, the locking means will automatically come into action and will hold the upper sectionin such vertical position, so that such said adjustment cannot be inadvertently altered. The invention in this broad aspect may take several forms; as an exempliication ol2 one form, I prefer that illustrated herein where the automatic locking means comprises a leall spring 12 of resilient metal fastened by means of screws 14 to the lace 16 of the lower section 2. The spring 12 is preferable of some length and extends longitudinally of the lower section 2 along such face 16. The spring 12 is slightly bent outwardly at a point 17 adjacent its lower end, so that when fastened in place on the section 2 the upper end of the spring will normally stand out from the face 16 of the lower section 2. The upper edge of the spring 12 is provided with laterally bent portions 18, which may take any shape but are preferably shown as spaced ears. These ears provide a substantially horizontal ledge or abutment against which the botto-m end of the upper section 4 may contact or rest when in extreme extended position, as shown in Figures 2 and 3. It desired, this lower face of the upper section 4: may be faced with a metal strip 20 fastened in place in a seat thereon by means of screw 22. This facing prevents injury to the lower end ol the upper section 4 due to its Contact `prefe-:ably 'form the lower section with a notch or pair of notches 26, directly opposite the ears 18 on the spring 12, so that when the spring is pushed inwardly the ears 1S will lie within the notches 2G and the spring can thus lie fiat against the lace 1G. This permits the upper section 4lto slide over the spring and to move in either direction. lVhen the upper section 4l is moved upwardly s shown in Figures 1 and 5, by reason of ivs resiliency it presses outwardly against the longitudinally extending ribs 27 on the inner face of the upper section fland holt s these two sections from rattling n'xovement. Due to the relatively broad face the spring 12 being wider than the distance between the ribs 27 on the inner or hidden face of the upper section 1l, this spring 12 will press against the ribs only and will not press against tne intermediate inner rface of the section Ll which as is well known is provided with divisional markings. Thus these markings are not marred or scraped by the spring 12 when the two sections are adjusted. In this position the spring 12 is ridden from view. On the other hand when the upper section et has been slid along to its extreme extended position, as shown in Figures 2, 3 and G, the lower end of the up per section Ll will clear 'the upper end oi" the spring' 12, so that the spring instantly moves outwardly and the cars 18 which lorm the ledge, snap past the metal plate 2O on the lower end of the section et and thus, under the action of gravity of this upper' section l, hold it l'rom downward movement; the upper section will thus be locked in its extreme extended position.

It will thus be seen that I have provided a very simple type of lock for accomplishing this purpose. The spring 12 as thus con structed is not only economical in manufacture and assembly, but it also is sure and positive in operation and permits the practically instant release of the upper section when once locked, as heretofore described, by merely pressing inwardly so that the ears house within the notches 24. It will also be apparent that when the two sections are in compactly arranged position, as shown in Figure 5, this spring, by pressing outwardly prevents them from rattling.

Having thus described my invent-ion what I claim as new and desire to secure by Letters Patent is:

1. In an extensible leveling rod, the combination of a irst section and an upper second section having divisional marks on its obverse and reverse faces, the reverse face having outstanding ribs extending parallel thereto and a leaf spring secured to the lower section and operable between such reverse face and the adjacent face of the other section for holding the sections when slid relatively in extreme position of extended ad-V justment, said spring at its free extremity 'being wider than lthe width of the space bef lower sections, saidupper section having a tween the ribs to engage the longitudinal ribs on the upper section whereby said spring is held out of contact with the divisional marks on saidr reverse face.

2. In a device of the class described, the combination of a lower section and an upper section slidable vertically thereon, said upper section having divisional marks on that face thereof which is adjacent to the face of the longitudinal projection thereon and a. leaf spring secured at one end to the lower section and adapted to contact against the longitudinal projection, said springat its freey extremity being adapted to bear against the projection to hold the upper section in extreme extended position relative to the lower section.

3. In an extension leveling rod, a lower leveling rod section,an upper section slidable on said lower section, one of said sections having a surface for receiving divisional marks, a longitudinal rib extending outwardly from said surface, and a leaf spring for locking said sections in extended position adapted to bear against the rib, said spring being carried by the'other rod section, whereby the surface having the divisional marks will be free from Vengagement with said leaf spring.

In witness whereof, I have hereunto subscribed my name.

ADOLPH LANGSN ER. 

